Switching to synthetic oil?

just got a 2004 with the 3.4 with 94,000 miles...has been using regular oil....would it be OK to switch to synthetic oil now?
Any advantages or disadvantages?

 

Its fine to switch between the two. This topic has been examined numerious times on TW. Do a search and you will find a ton of threads on this topic.

 

Don't know if it matters with that low of mileage, but when I switched over one time, it was not good... 270k+ miles though. I read and heard that synthetic tends to "clean up" some of the sludge and build up inside your engine, exposing old, dry gaskets and causing leaks. I do not recommend switching over if you are high mileage.

 

Some good reading below, its like 60 pages so it should keep you busy for awhile.

https://www.tacomaworld.com/threads/synthetic-oil.21223/page-12#post-669145

 

I bought a 2.4L SR5 04 with 30k miles. I used dinosaur oil until about 70k miles. I then started using synthetic, and increased my oil change interval by about 1500 miles. I continued this until I traded the truck in with 217k miles. Purely anecdotal, but no issues noted.

 

I switched over my 3.4 at 200,000 miles and it doesn't burn a drop or even get dirty. Castrol edge 5w30.

 

I switched my 3.4 over around 115k. Use only mobile 1 synthetic 5w30. Did a few changes at 5,000 miles. Then had an oil analysis done at 8,500. Am now comfortably waiting until 10,000 miles. A healthy 3.4 with good oil and filter should have no problems at all switching to synthetic.

Edit: Let me know if anyone wants to see the OA results from Blackstone.

 

Switching to synthetic won't hurt anything. However, if it were me, I would go with a high mileage formula. It contains seal and gasket conditioners to help prevent leaks. M1 HM is available just about anywhere. But any HM synthetic will be fine

 

Except he said he is using oil, which I presume that synthetics makes it worse. Some people might not I guess, but synthetic oil is not good to use on a truck with bad gaskets and/or rings...

 

https://mobiloil.com/en/article/car-maintenance/learn-about-motor-oil-facts/high-mileage-motor-oil

 

That old advise presumed that the reason your seals were working in the first place was due to sludge and debris. That means the problem wasn't the oil but that your seals were worn and needed to be replaced. These days oils and engines are improved and cleaner so the switch over isn't as dramatic. Conventional oils are highly refined to almost be synthetic, what's called synthetic is less distinct, etc.

 

If you're worried, you can try a semi-synthetic or high mileage synthetic first. If no leaks then you can move to a full synthetic next oil change.

 

Just my experience here. Got the 04 TRD with about 96k miles . Not sure what type of oil PO used. But immediately switched to Royal Purple (yes I really like this truck.....) 5w30 in winter and 10w30 in summer. No probs. Now 145K miles

 

I started using RP HMX 5w30 high when I bought my Tacoma w/ 170k miles on it. Been using it ever since. No leaks or burning of oil. The dipstick always reads the same. It now has just a little over 260k miles.

 

Yes, it is safe to switch to synthetic oil. The thing is that you may see leaks appear because of old and worn out gaskets. Since synthetic has smaller molecules than regular oil, it can seep through little cracks and tears in the gaskets that regular oil couldn't because of it's bigger molecules.

Synthetic does not cause leaks, it just highlights issues with worn out gaskets. Issues that would have eventually resulted in leaks anyway, even with regular oil

Actually, the "seal conditioner" is just an additive that causes gaskets to swell. Swollen gaskets will most probably cause leaks if you ever switch back to non high-mileage or synthetic oil

 

Switched from dino oil to semi synthetic at 150k, went to high mileage full synthetic around 160k, currently at 177k with no adverse affects. The truck starts, runs and drives so much smoother.

Glad I made the switch and my 3.4 will thank me during our -40 f winters.

 

If you're using a HM formula on a high mileage engine....why would you switch back? An engine will never have fewer miles on it that what it does at this moment.

 

Is royal purple a good oil?

 

Nothing wrong with Royal Purple. It's a bit pricey and may not be as readily available as Mobil 1, Penzoil, Valvoline, etc....but it's a quality product.

Honestly...all oil, synthetic and conventional are good these days. I wouldn't over think this. It's easy to do. Just pick out a HM formula synthetic and run with it.

https://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=cfrm